1. Field of the Invention
The present invention relates generally to a magnetic tape recording and/or reproducing apparatus (hereinafter referred to as a magnetic tape recording/reproducing apparatus), and more particularly, to a digital audio tape recorder (hereinafter xe2x80x9cDATxe2x80x9d) streamer used as a large-capacity external memory back-up device for computers.
2. Description of the Related Art
The DAT streamer uses a DAT tape cassette. The DAT tape cassette is loaded in the DAT streamer, a magnetic tape is extracted from the DAT tape cassette by tape guide posts in a tape loading operation and thereafter the magnetic tape is driven between a capstan and a pinch roller. Recording information to and reproducing information from the magnetic tape is carried out by a high-speed rotary drum, that is, a rotary head. After recording and reproduction is completed, the magnetic tape is returned to the DAT tape cassette in a tape unloading operation, after which the DAT tape cassette may be ejected.
In order for the DAT tape cassette to be ejected smoothly, it is important that the tape guide posts having flanges at a top and a bottom thereof be securely returned to their original positions at the stage at which the tape unloading operation is completed. If the tape guide posts are not returned to their original positions, then when the DAT tape cassette is ejected a lengthwise edge of the magnetic tape may contact an upper flange of the top of the tape guide posts, thus damaging the magnetic tape.
In order to facilitate an understanding of the problem, a description will now be given of the related art.
The conventional DAT streamer tape loading mechanism has a motor, a cam gear, a cam plate, a cam plate arm, and tape guide posts. When the DAT tape cassette is loaded, the motor rotates the cam gear. The rotation of the cam gear is transmitted to the cam plate via the cam plate arm, the cam plate moves, the tape guide posts move in a direction away from the DAT tape cassette and the operation of loading the tape by pulling the magnetic tape out from the DAT tape cassette is performed. When recording and reproduction are stopped, the motor again rotates the cam gear, the rotation of the cam gear is transmitted to the cam plate via the cam plate arm, the cam plate moves so as to move the tape guide posts in a direction so as to return to the DAT tape cassette and the magnetic tape is returned to within the DAT tape cassette in a tape unloading operation.
Among those parts related to the tape guide posts is a spring for pressing the tape guide posts against a stopper near the rotary drum. In the tape loading operation described above, the operation terminates in a state in which the spring is stretched and the tape guide posts are pressed against the stopper due to the spring force of the stretched spring, and there is no problem.
In the tape unloading operation, however, there is no pressing of the tape guide posts against the stopper, so the position of the tape guide posts when the tape unloading operation terminates is dependent upon the accumulation of dimensional tolerances of the various parts that comprise the tape loading mechanism and the precision with which the DAT streamer has been assembled, and hence varies with each assembled DAT streamer. Normally such variation does not present a problem. On occasion, however, the tape guide posts end their travel at a position relatively far from their proper final position, and when the DAT tape cassette is ejected in such cases there is a possibility that the lengthwise edge of the magnetic tape hits the top flanges of the guide posts, thus damaging the magnetic tape.
In actuality, in those cases in which the tape guide posts do not fully return to their original positions the positions at which the parts are mounted are adjusted so as to permit the tape guide posts to return to their original positions. However, such adjustment is troublesome.
Accordingly, it is an object of the present invention to provide an improved and useful magnetic tape recording/reproducing apparatus in which the disadvantages described above are eliminated.
Another and more specific object of the present invention is to provide a magnetic tape recording/reproducing apparatus in which a spring urges the tape guide posts back to their original positions.
The above-described objects of the present invention are achieved by a magnetic tape recording/reproducing apparatus comprising:
a tape loading mechanism which performs a tape loading operation by moving a post from an original position to a loading position so as to extract a magnetic tape from a loaded cassette and a tape unloading operation to return the magnetic tape to within the cassette,
the tape loading mechanism comprising a spring member, the spring member being disposed so as to deform during the tape unloading operation, the tape unloading operation terminating after the spring member deforms, the deformed spring member urging the post to return to the original position thereof.
According to the invention described above, regardless of the cumulative tolerance that is the accumulation of the tolerances of the individual parts that together form the tape loading mechanism and regardless of the lack of precision with which the magnetic tape recording/reproducing apparatus is assembled, the loading posts 12, 13 can be urged by the spring member and reliably returned to their original positions in a state in which the tape loading mechanism terminates a tape unloading operation. Accordingly, the magnetic tape does not get caught on the loading posts either when one cassette is ejected or when another cassette is loaded into the apparatus. Additionally, it is possible to do without the adjusting mechanism for slightly shifting the installation positions of the parts so that the loading posts return to their original positions, such adjusting mechanism required conventionally whenever the loading posts do not fully return to those original positions.
Additionally, the above-described objects of the present invention are also achieved by a magnetic tape recording/reproducing apparatus comprising:
a tape loading mechanism which performs a tape loading operation by moving a post from an original position to a loading position so as to extract a magnetic tape from a loaded cassette and a tape unloading operation to return the magnetic tape to within the cassette,
the tape loading mechanism comprising:
a cam plate that moves in a first direction from an original position so as to cause the post to extract the magnetic tape from the loaded cassette, the cam plate moving in a second direction opposite to the first direction to the original position thereof and moving the post to the original position thereof so as to cause the post to return the magnetic tape to within the cassette;
a drive cam plate mounted on the cam plate so as to be slidably movable within a predetermined range in the first direction and the second direction, a force for moving the cam plate acting on the drive cam plate; and
a spring member disposed between the cam plate and the drive cam plate,
the tape unloading operation terminating after the cam plate returns to the original position thereof and the drive cam plate moves relative to the cam plate while the spring member is deformed, the deformed spring member urging the post to return to the original position thereof.
According to the invention described above, a simple structure for urging the loading posts back to their original positions can be achieved, comprising a cam plate, drive cam plate and spring member.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.